Perieccrine inflammation may be observed in several different dermatoses, but true permeation of the secretory coil by lymphocytes (lymphocytic syringotropism) is a rather uncommon finding, usually observed in mycosis fungoides (MF—syringotropic MF). Rare cases of syringotropic lichen striatus and lymphocytic autoimmune hidradenitis showing a similar pattern have been described as well. We describe an exceptional case of lichen planus (LP) characterized by marked lymphocytic syringotropism with focal hyperplasia of the eccrine epithelium. Histopathology was characterized by the combination of features of conventional LP, prominent permeation of the secretory portion of the eccrine glands by reactive lymphocytes, and focal involvement of a hair follicle. Syringotropic LP may be regarded as a histologic mimicker of syringotropic MF, thus representing a potential diagnostic pitfall.
*Research Unit Dermatopathology, Department of Dermatology, Medical University of Graz, Graz, Austria;
†Department of Dermatology, University of Rome “Tor Vergata,” Rome, Italy; and
‡Anatomic Pathology, Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.
Correspondence: Lorenzo Cerroni, MD, Department of Dermatology, Medical University of Graz, Auenbruggerplatz 8, A-8036 Graz, Austria (e-mail: email@example.com).
The authors declare no conflicts of interest.